A stator of an electrical machine (cf. USSR Inventor's Certificate No. 340,024, Cl. H 02 k 3/46) is known, wherein the winding is partially received in the core slots and partially comes out into the air gap. The stator core is provided with slots wherein the bars and means for fastening the bars in the radial direction are partially accommodated.
Such stators are of a complicated design and require an additional space to accommodate the fastening means, which reaches outside the space occupied by the winding. The result is a low space factor of the electrical machine's air gap.
Another stator of an electrical machine (cf. USSR Inventor's Certificate No. 613,447) is known, which comprises a slotted core with slots of a triangle-shaped cross-section, and a multilayer bar winding, wherein the bars of adjacent layers are staggered to adjoin one another on two sides. The bars of the lower layer of the multilayer bar winding are partially received in the slots of the stator core and partially come out into the air gap which accommodates the remaining layers rigidly secured with respect to the lower layer by insulating wedge members interposed between the upper layer of the winding and a cylinder of an insulating material.
The cylinder has to bear all the radial forces, thereby requiring it to be of a considerable thickness. However, this requirement accounts for a reduced space factor of the electrical machine's air gap and effects the performance of the stator as a whole.
Another disadvantage of the stator under review is its inadequate maintainability. Replacement even of a single bar necessitates a removal of the cylinder, which, in turn, makes it necessary to dismantle the whole winding.